Sound signal acquisition at lower number of samples

Hi

Good day.

I am beginner to LabVIEW software and recently working with LabVIEW 2017 for data acquisition.  

I have to acquire respiratory sound signals continuously using a digital stethoscope connected to PC via audio jack. I need to perform multiple recordings in one acquisition, so I added a waveform chart into the vi for continuous acquisition and write to measurement file for saving data of multiple recordings.

I need to acquire sound signals at lower number of samples (such as 100Hz). When I change the number of samples from 10000 to 100, it showing some errors. 

How could I acquire the sound signals at lower number of samples? Could anyone guide me on this?

Attached here is the vi responsible for sound acquisition and errors shown. 

Thanks.

Regards,

Priya